[v4 2/4] arm64: kvm: add kvm cpu hotplug

AKASHI Takahiro
2015-05-08T01:19:10Z

This patch allows cpu cores to be up and down by adding
kvm_arch_hardware_enable/isable(). This way, especially in kexec case,
cores are reset to initial states and kexec can gracefully shutdown the
system and reboot a new kernel from EL2.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
---
arch/arm/include/asm/kvm_host.h | 1 -
arch/arm/kvm/arm.c | 29 +++++++++++++++++++----------
arch/arm64/include/asm/kvm_host.h | 1 -
3 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 41008cd..ca97764 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -237,7 +237,6 @@ void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot);

struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);

-static inline void kvm_arch_hardware_disable(void) {}
static inline void kvm_arch_hardware_unsetup(void) {}
static inline void kvm_arch_sync_events(struct kvm *kvm) {}
static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 251ab9e..e989925 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -87,11 +87,6 @@ struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void)
return &kvm_arm_running_vcpu;
}

-int kvm_arch_hardware_enable(void)
-{
- return 0;
-}
-
int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
@@ -885,6 +880,9 @@ static void cpu_init_hyp_mode(void *dummy)
unsigned long stack_page;
unsigned long vector_ptr;

+ if (__hyp_get_vectors() != hyp_default_vectors)
+ return;
+
/* Switch from the HYP stub to our own HYP init vector */
__hyp_set_vectors(kvm_get_idmap_vector());

@@ -921,6 +919,10 @@ static int hyp_init_cpu_notify(struct notifier_block *self,
if (__hyp_get_vectors() == hyp_default_vectors)
cpu_init_hyp_mode(NULL);
break;
+ case CPU_DYING:
+ case CPU_DYING_FROZEN:
+ kvm_cpu_reset(NULL);
+ break;
}

return NOTIFY_OK;
@@ -936,6 +938,7 @@ static int hyp_init_cpu_pm_notifier(struct notifier_block *self,
void *v)
{
if (cmd == CPU_PM_EXIT &&
+ kvm_arm_get_running_vcpu() &&
__hyp_get_vectors() == hyp_default_vectors) {
cpu_init_hyp_mode(NULL);
return NOTIFY_OK;
@@ -1039,11 +1042,6 @@ static int init_hyp_mode(void)
}

/*
- * Execute the init code on each CPU.
- */
- on_each_cpu(cpu_init_hyp_mode, NULL, 1);
-
- /*
* Init HYP view of VGIC
*/
err = kvm_vgic_hyp_init();
@@ -1144,6 +1142,17 @@ out_err:
return err;
}

+int kvm_arch_hardware_enable(void)
+{
+ cpu_init_hyp_mode(NULL);
+ return 0;
+}
+
+void kvm_arch_hardware_disable(void)
+{
+ kvm_cpu_reset(NULL);
+}
+
/* NOP: Compiling as a module not supported */
void kvm_arch_exit(void)
{
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 6a8da9c..831e6a4 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -262,7 +262,6 @@ static inline void vgic_arch_setup(const struct vgic_params *vgic)
}
}

-static inline void kvm_arch_hardware_disable(void) {}
static inline void kvm_arch_hardware_unsetup(void) {}
static inline void kvm_arch_sync_events(struct kvm *kvm) {}
static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
--
1.7.9.5